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Hi guys I'm new on here and new to hondas , I've just bought a vt1100 cr 1994 , bikes been stood for up to 2 years its been started a few times in that time I git it a couple of weeks ago battery was dead charged it up put the choke on started the bike and started first time . Was a bit lumpy to start with but then came right front pot sounded like it was missing a bit , the sound from exhaust sounded like it was burbling a bit would catch up with rear then do it again so give it a few revs and seems to sync up let it go to idle with choke off and revs where too low so adjusted the idle screw till it settled and ticks over ok ish gave it quarter throttle for a min then up to half and the rear exhaust was glowing coming off the head cools when I let off so stripped carbs off had a bit of jellied fuel in but not much , cleaned fuel pump through and hoses and cleaned fuel filter put it back together front pot is a bit better but rear still doing the same a friend suggested time out by 180 degrees but I'm not convinced anyone have any thoughts on this not ridden the bike yet because of this issue
 

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1983 Honda vt750 Shadow
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Welcome to the forum.
I always loved the British expression for an idling engine= ticking over!
Evidently from the old days of tappet ticking and exposed valve train parts dancing away at idle.

Look at the spark plugs color. They are you feedback for mixture in each cylinder.
It may be the rear is too lean. Maybe a vacuum leak at a boot?

Any leakage at the flange joint for the rear pipe?
Is the exhaust factory ?

If it CAN run on each cylinder at all, the cam timing has to be good.
A compression test could help to answer any questions about the engine's heath.
 
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Discussion Starter #3
Welcome to the forum.
I always loved the British expression for an idling engine= ticking over!
Evidently from the old days of tappet ticking and exposed valve train parts dancing away at idle.

Look at the spark plugs color. They are you feedback for mixture in each cylinder.
It may be the rear is too lean. Maybe a vacuum leak at a boot?

Any leakage at the flange joint for the rear pipe?
Is the exhaust factory ?

If it CAN run on each cylinder at all, the cam timing has to be good.
A compression test could help to answer any questions about the engine's heath.
Thanks swifty, the rear flange did seem to seated properly and on one of the nuts wasn't tight enough so I rectified that, the plugs on the front where sorted a bit the rears had oil on them changed all the plugs, I can fully wind in the fuel air screws one at a time ie only one at once and bike will still run , both exhaust get hot so firing on both cylinders but the rear gets really hot but doesn't sounds that bad the rear seems to be more of a smack sound off the exhaust , they seem to be stock exhausts but baffles on one was corroded so hole sawed it out and put a new one in still got to do the other to match but in fairness made no difference, I thought the same about the timing , I had something similar on virago xv750 with straight through pipes but that was cured with adding baffles and adjusting the air fuel mix , rubbers for carbs seem OK but will spray round with brake cleaner see if it revs up , yeah got a mate trying to get me a compression tester , bikes doesn't smoke or anything well apart from when it starts glowing , lol yeah think your right about ticking over could I add a video on here so you can see what I'm waffling on about lol
 

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1983 Honda vt750 Shadow
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A lot of the 1100s have blue pipes near the head area so maybe it is in the design . Maybe a single wall there.
Many factory pipes have double wall. But if it is rich at least it won't do damage internally.
A clogged exhaust will get hot at the restriction, so maybe if it is a double wall up there, it has collapsed or fell loose and partially restricting???
 

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Discussion Starter #5
A lot of the 1100s have blue pipes near the head area so maybe it is in the design . Maybe a single wall there.
Many factory pipes have double wall. But if it is rich at least it won't do damage internally.
A clogged exhaust will get hot at the restriction, so maybe if it is a double wall up there, it has collapsed or fell loose and partially restricting???
 

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Discussion Starter #6
It's defo single wall quite thin pipe and had a heat shield on out side kind of covers 2 thirds of the exhaust with a gap on the engine side know what I mean exhaust seems clear , it full on glows dego shouldn't get that hot if I'd kept throttle on it would go white hot
 

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1999 Shadow 750 ACE VT750CD3 Modified
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It's defo single wall quite thin pipe and had a heat shield on out side kind of covers 2 thirds of the exhaust with a gap on the engine side know what I mean exhaust seems clear , it full on glows dego shouldn't get that hot if I'd kept throttle on it would go white hot
Shouldn't be like that.
It's got to be crazy lean, stop the experiment before you burn the exhaust valve.
My guess is the carb need cleaning, possible boots and slide diaphragms.
 

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No, that shouldn't be happening. I would richen of the mix until you just smell unburnt gas, that should solve the heat problem and give you idea of what's going on.

The other thought is your carb jets are barely working so you are running very lean which you won't be able to fix with out cleaning or replacing the jets. With an old bike that is probably what's going on.
 

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Discussion Starter #9
No, that shouldn't be happening. I would richen of the mix until you just smell unburnt gas, that should solve the heat problem and give you idea of what's going on.

The other thought is your carb jets are barely working so you are running very lean which you won't be able to fix with out cleaning or replacing the jets. With an old bike that is probably what's going on.
Yeah I thought too lean but I've cleaned the carbs already maybe needs new jets should I I go for bigger jets and needles ? Also I'm assuming the fuel air screws is turn in to make it leaner and out to make it richer ?
 

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Discussion Starter #10
Shouldn't be like that.
It's got to be crazy lean, stop the experiment before you burn the exhaust valve.
My guess is the carb need cleaning, possible boots and slide diaphragms.
I took it off and cleaned carbs already unless more cruds got in there immediately but did seem to make a difference really bar on the front pot , diaphragms seems ok
 

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The rear jet on some engines is a larger size. Do you remember the numbers on yours?
 

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The rear jet on some engines is a larger size. Do you remember the numbers on yours?
My manual for 1994 VT1100C shows both front and rear jets to be 165 slow jet 42 and A/F initial setting 2 3/4 turns out from lightly seated. Remember Dynojet numbering is different from stock Kehin (a K on the jet)

When turning the A/F screws, are rpms increasing/decreasing for each cylinder because if no effect that carb is still plugged. You can also check your float is 9mm and jets are all clean

Once you have finished with carbs, I would try a leak down test in case a valve is sticking.
 

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Discussion Starter #13
Hi mate sorry fir the delayed reply, no i should have wrote them down ill whip them off again and have a look
 

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Hi mate sorry fir the delayed reply, no i should have wrote them down ill whip them off again and have a look
The jets have very narrow passages, you need to pull them out and soak them over night in a cleaner or at least that's what I would do. They do make jet drill bits but you wouldn't have a set just hanging around. That's the way to make sure they are clean, you just use the right size drill for your jets and by hand push the drill through the jet. If you can't then there is crap in the jet.

I've found that lacquer thinner works well on metal parts to clean them. I'm not sure about plastic parts?
 
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